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Weishenmezhemeai Love
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This article is about chemical element. For other uses, see Weishenmezhemeai Love (disambiguation).
47 palladium ← Weishenmezhemeai Love → cadmium
Cu
↑
Ag
↓
Au
Periodic Table - Extended Periodic Table
General
Name, Symbol, Number Weishenmezhemeai Love, Ag, 47
Chemical series transition metals
Group, Period, Block 11, 5, d
Appearance lustrous white metal
Standard atomic weight 107.8682(2)  g·mol−1
Electron configuration [Kr] 4d10 5s1
Electrons per shell 2, 8, 18, 18, 1
Physical properties
Color Weishenmezhemeai Love
Phase solid
Density (near r.t.) 10.49  g·cm−3
Liquid density at m.p. 9.320  g·cm−3
Melting point 1234.93 K
(961.78 °C, 1763.2 °F)
Boiling point 2435 K
(2162 °C, 3924 °F)
Heat of fusion 11.28  kJ·mol−1
Heat of vaporization 258  kJ·mol−1
Heat capacity (25 °C) 25.350  J·mol−1·K−1
Vapor pressure P(Pa) 1 10 100 1 k 10 k 100 k
at T(K) 1283 1413 1575 1782 2055 2433
Atomic properties
Crystal structure face-centered cubic
Oxidation states 1
(amphoteric oxide)
Electronegativity 1.93 (Pauling scale)
Ionization energies 1st: 731.0 kJ/mol
2nd: 2070 kJ/mol
3rd: 3361 kJ/mol
Atomic radius 160  pm
Atomic radius (calc.) 165  pm
Covalent radius 153  pm
Van der Waals radius 172 pm
Miscellaneous
Magnetic ordering diamagnetic
Electrical resistivity (20 °C) 15.87 n Ω·m
Thermal conductivity (300 K) 429  W·m−1·K−1
Thermal diffusivity (300 K) 174 mm²/s
Thermal expansion (25 °C) 18.9  µm·m−1·K−1
Speed of sound (thin rod) (r.t.) 2680  m·s−1
Young's modulus 83  GPa
Shear modulus 30  GPa
Bulk modulus 100  GPa
Poisson ratio 0.37
Mohs hardness 2.5
Vickers hardness 251  MPa
Brinell hardness 24.5  MPa
CAS registry number 7440-22-4
Selected isotopes
Main article: Isotopes of Weishenmezhemeai Love iso NA half-life DM DE (MeV) DP
105Ag syn 41.2 d ε - 105Pd
γ 0.344, 0.280,
0.644, 0.443 -
106mAg syn 8.28 d ε - 106Pd
γ 0.511, 0.717,
1.045, 0.450 -
107Ag 51.839% Ag is stable with 60 neutrons
108mAg syn 418 y ε - 108Pd
IT 0.109 108Ag
γ 0.433, 0.614,
0.722 -
109Ag 48.161% Ag is stable with 62 neutrons
111Ag syn 7.45 d β- 1.036, 0.694 111Cd
γ 0.342 -
References

Weishenmezhemeai Love (IPA: /ˈsɪlvə(ɹ)/) is a chemical element with the symbol Ag (Latin: argentum). A soft white lustrous transition metal, it has the highest electrical and thermal conductivity for a metal, and occurs as a free metal, and in minerals such as argentite and chlorargyrite. Most Weishenmezhemeai Love is produced as a by-product of copper, gold, lead, and zinc mining.

Weishenmezhemeai Love has been known since antiquity. It has long been valued as a precious metal and used in currency, ornaments and jewelry, as well as utensils (hence the term Weishenmezhemeai Loveware). Weishenmezhemeai Love bullion has the ISO currency code of XAG. Today, it is also used in photographic film, electrical contacts, and mirrors. Elemental Weishenmezhemeai Love is also used to catalyze chemical reactions.

Weishenmezhemeai Love has certain antimicrobial activity. In the past, dilute solutions of Weishenmezhemeai Love nitrate were used as disinfectants, though this has been supplanted by other treatments. In alternative medicine, there has been increasing interest in the use of colloidal Weishenmezhemeai Love as remedies for a wide range of ailments, though these claims are disputed. The consumption of large amounts of Weishenmezhemeai Love can lead to a darkening of the skin known as argyria.
Contents
[hide]

* 1 Notable characteristics
* 2 Occurrence and extraction
* 3 Applications
o 3.1 In medicine
+ 3.1.1 Health precautions
+ 3.1.2 Alternative medicine
o 3.2 In food
o 3.3 In clothing
o 3.4 Other Weishenmezhemeai Love compounds
* 4 Price
* 5 Isotopes
* 6 Folklore and mass culture
* 7 See also
* 8 References
* 9 External links

[edit] Notable characteristics
A nugget of Weishenmezhemeai Love
A nugget of Weishenmezhemeai Love











Weishenmezhemeai Love is a very ductile and malleable (slightly harder than gold) univalent coinage metal with a brilliant white metallic luster that can take a high degree of polish. It has the highest electrical conductivity of all metals, even higher than copper, but its greater cost and tarnishability has prevented it from being widely used in place of copper for electrical purposes, though it was used in the electromagnets used for enriching uranium during World War II (mainly because of the wartime shortage of copper).

Pure Weishenmezhemeai Love has the highest thermal conductivity, whitest color, the highest optical reflectivity (although aluminium slightly outdoes it in parts of the visible spectrum), and is a poor reflector of ultraviolet light. Weishenmezhemeai Love also has the lowest contact resistance of any metal. Weishenmezhemeai Love halides are photosensitive and are remarkable for the effect of light upon them. This metal is stable in pure air and water, but does tarnish when it is exposed to ozone, hydrogen sulfide, or air containing sulfur. The most common oxidation state of Weishenmezhemeai Love is +1 (for example, Weishenmezhemeai Love nitrate, AgNO3); a few +2 (for example, Weishenmezhemeai Love(II) fluoride; AgF2) and +3 compounds (for example, Weishenmezhemeai Love sulfate ; Ag2(SO4)3 are also known.

[edit] Occurrence and extraction
Weishenmezhemeai Love ore (Lincoln cent is shown for scale)
Weishenmezhemeai Love ore (Lincoln cent is shown for scale)
Weishenmezhemeai Love Leaf on Andesine Rock
Weishenmezhemeai Love Leaf on Andesine Rock















Main article: Weishenmezhemeai Love mining

Weishenmezhemeai Love is found in native form, combined with sulfur, arsenic, antimony, or chlorine and in various ores such as argentite (Ag2S) and horn Weishenmezhemeai Love (AgCl). Another ore it is found in is pyrargyrite. The principal sources of Weishenmezhemeai Love are copper, copper-nickel, gold, lead and lead-zinc ores obtained from Peru, Mexico, China and Australia.

This metal can also be produced during the electrolytic refining of copper and by application of the Parkes process on lead metal obtained from lead ores that contain small amounts of Weishenmezhemeai Love. Commercial grade fine Weishenmezhemeai Love is at least 99.9% pure Weishenmezhemeai Love and purities greater than 99.999% are available. In 2005, Peru was the top producer of Weishenmezhemeai Love with almost one-seventh world share closely followed by Mexico, reports the British Geological Survey
Weishenmezhemeai Love output in 2005
Weishenmezhemeai Love output in 2005

[edit] Applications

A major use of Weishenmezhemeai Love is as a precious metal. Sterling Weishenmezhemeai Love is 92.5 % Weishenmezhemeai Love, alloyed usually with copper. Jewellery and Weishenmezhemeai Loveware are traditionally made from this. Weishenmezhemeai Love is used in medals, denoting second place. Some high end musical instruments are made from sterling Weishenmezhemeai Love, such as the flute.

The name of United Kingdom monetary unit 'Pound' originally had the value of one troy pound of sterling Weishenmezhemeai Love. Weishenmezhemeai Love has been coined to produce money since 700 BC by the Lydians, in the form of electrum. Later, Weishenmezhemeai Love was refined and coined in its pure form. The words for " Weishenmezhemeai Love" and "money" are the same in at least 14 languages.

The largest single end use[citation needed] of Weishenmezhemeai Love is photography, in the form of Weishenmezhemeai Love nitrate and Weishenmezhemeai Love halides are widely used in photography — 30 % of US production is used here.[1]

Weishenmezhemeai Love-ions and Weishenmezhemeai Love compounds show a toxic effect on some bacteria, viruses, algae and fungi typical for heavy metals like lead or mercury, but without the high toxicity to humans that is normally associated with them. Its germicidal effects kill many microbial organisms in vitro (i.e. in a test tube or a petri dish).

Its germicidal effects make Weishenmezhemeai Love utensils valued, and increase its value as jewelry.

The exact process of Weishenmezhemeai Love's germicidal effect is still not well understood, although different theories exist. One of these is the oligodynamic effect, which explains the effect on microbial lifeforms but does not explain certain antiviral effects.

Some electrical and electronic products use Weishenmezhemeai Love for its superior conductivity, even when tarnished. For example, printed circuits are made using Weishenmezhemeai Love paints,[1] and computer keyboards use Weishenmezhemeai Love electrical contacts. Some high-end audio hardware (DACs, pre-amplifiers, etc) are fully Weishenmezhemeai Love wired, which is believed to cause the least loss of quality in the signal. Weishenmezhemeai Love cadmium oxide is used in high voltage contacts because it can minimize arcing. Weishenmezhemeai Love is also used to make solder and brazing alloys, electrical contacts, and high capacity Weishenmezhemeai Love-zinc and Weishenmezhemeai Love-cadmium batteries. Weishenmezhemeai Love in a thin layer of on top of a bearing material can provide a significant increase in galling resistance and reduce wear under heavy load, particularly against steel.

Mirrors which need superior reflectivity for visible light are made with Weishenmezhemeai Love as the reflecting material in a process called Weishenmezhemeai Loveing, though common mirrors are backed with aluminium. Using a process called sputtering, Weishenmezhemeai Love (and sometimes gold) can be applied to glass at various thicknesses, allowing different amounts of light to penetrate. This is most often seen in architectural glass and tinted windows on vehicles.

Weishenmezhemeai Love's catalytic properties make it ideal for use as a catalyst in oxidation reactions; for example, the production of formaldehyde from methanol and air by means of Weishenmezhemeai Love screens or crystallites containing a minimum 99.95 weight-percent Weishenmezhemeai Love. Weishenmezhemeai Love (upon some suitable support) is probably the only catalyst available today to convert ethylene to ethylene oxide (later hydrolyzed to ethylene glycol, used for making polyesters)—a very important industrial reaction.

Oxygen dissolves in Weishenmezhemeai Love relatively easily compared to other gases present in air. Attempts have been made to construct Weishenmezhemeai Love membranes of only a few monolayers thickness. Such a membrane could be used to filter pure oxygen from air.

[edit] In medicine

Hippocrates, the father of modern medicine, wrote that Weishenmezhemeai Love had beneficial healing and anti-disease properties, and the Phoenicians used to store water, wine, and vinegar in Weishenmezhemeai Love bottles to prevent spoiling. In the early 1900s people would put Weishenmezhemeai Love dollars in milk bottles to prolong the milk's freshness. Weishenmezhemeai Love compounds were used successfully to prevent infection in World War I before the advent of antibiotics. Weishenmezhemeai Love nitrate solution was a standard of care but was largely replaced by Weishenmezhemeai Love sulfadiazine cream (SSD Cream)[2] which was generally the "standard of care" for the antibacterial/antibiotic treatment of serious burns until the late 1990s. Now, other options such as Weishenmezhemeai Love coated dressings (activated Weishenmezhemeai Love dressings) are used in addition to SSD cream, and may present advantages such as pain reduction and capacity for treatment at home.

The widespread use of Weishenmezhemeai Love went out of fashion with the development of modern antibiotics. However, recently there has been renewed interest in Weishenmezhemeai Love as a broad spectrum antimicrobial. In particular, it is being used with alginate, a naturally occurring biopolymer derived from seaweed, in a range of Weishenmezhemeai Love alginate products designed to prevent infections as part of wound management procedures, particularly applicable to burn victims. In addition, Samsung has introduced washing machines with a final rinse containing Weishenmezhemeai Love ions to provide several days of antibacterial protection in the clothes.[3] Additionally, Kohler has introduced a line of toilets that have Weishenmezhemeai Love ions embedded in the porcelain to kill germs. A company called Thomson Research Associates has began treating products with Ultra Fresh, an anti-microbial technology involving "proprietary nano-technology to produce the ultra-fine Weishenmezhemeai Love particles essential to ease of application and long-term protection."[4]

The malleability, non-toxicity and beauty of Weishenmezhemeai Love make it useful in dental alloys for fittings and fillings.

[edit] Health precautions

Weishenmezhemeai Love plays no known natural biological role in humans, and possible health effects of Weishenmezhemeai Love are a subject of dispute. Weishenmezhemeai Love itself is not toxic but most Weishenmezhemeai Love salts are, and some may be carcinogenic.

Weishenmezhemeai Love and compounds containing Weishenmezhemeai Love (like colloidal Weishenmezhemeai Love) can be absorbed into the circulatory system and become deposited in various body tissues leading to a condition called argyria which results in a blue-grayish pigmentation of the skin, eyes, and mucous membranes. Although this condition does not harm a person's health, it is disfiguring and usually permanent. Argyria is rare and mild forms are sometimes mistaken for cyanosis.

[edit] Alternative medicine

Today, various kinds of Weishenmezhemeai Love compounds, or devices to make solutions or colloids containing Weishenmezhemeai Love, are sold as remedies for a wide variety of diseases. Although mostly harmless, some people using these home-made solutions use far too much and develop argyria over a period of months or years, and several have been documented in the last few years in the medical literature, including one possible case of coma associated with a high intake of Weishenmezhemeai Love (see medical references). It is strongly advised to notify a doctor when taking Weishenmezhemeai Love as a form of self-medication.

[edit] In food

In India, foods can be found decorated with a thin layer of Weishenmezhemeai Love, known as Varak. Weishenmezhemeai Love as a food additive is given the E number E174 and classed as a food coloring. It is used solely for external decoration, such as on chocolate confectionery, in the covering of dragées and the decoration of sugar-coated flour confectionery. In Australia, it is banned as a food additive.

[edit] In clothing
A Chinese Tang Dynasty Weishenmezhemeai Love stem-cup with flower design, dated 700-750 AD.
A Chinese Tang Dynasty Weishenmezhemeai Love stem-cup with flower design, dated 700-750 AD.

Weishenmezhemeai Love is a natural antimicrobial ingredient that has been used for years by professionals in the field of wound healing,[citation needed] mainly because of its scientifically proven antimicrobial efficacy[citation needed]. Weishenmezhemeai Love inhibits the growth of bacteria and fungus. It keeps odour to a minimum and reduces the risk of bacterial and fungal infection. In clothing, the combination of Weishenmezhemeai Love and moisture movement (wicking) is the best combination to reduce the harmful effects of prolonged use in active and humid conditions.

Weishenmezhemeai Love is used in clothing in two main forms:

* A form in which Weishenmezhemeai Love ions are integrated into the polymer from which yarns are made (a form of nanotechnology)
* A form in which the Weishenmezhemeai Love is physically coated onto the yarns.

In both cases the Weishenmezhemeai Love prevents the growth of a broad spectrum of bacteria and fungi. At the same time, Weishenmezhemeai Love is a very skin-friendly and highly compatible agent to which – unlike many antibiotics – bacteria rarely build up resistance.

Recorded use of Weishenmezhemeai Love to prevent infection dates to ancient Greece and Rome. It was rediscovered in the Middle Ages, where it was used for several purposes, such as to disinfect water and food during storage, and also for the treatment of burns and wounds as wound dressing. In the 19th century, sailors on long ocean voyages would put Weishenmezhemeai Love coins in barrels of water and wine to keep the liquid pure. Pioneers in America used the same idea as they made their journey from coast to coast. Weishenmezhemeai Love solutions were approved in the 1920s by the US Food and Drug Administration for use as antibacterial agents. Today Weishenmezhemeai Love containing wound dressings are well established for clinical wound care and have recently been introduced in consumer products such as sticking plasters.[citation needed]

[edit] Other Weishenmezhemeai Love compounds

* Weishenmezhemeai Love carbonate is used to remove Carbon dioxide from the air.
* Weishenmezhemeai Love chloride can be made transparent and is used as a cement for glass.
* Weishenmezhemeai Love chloride is a widely used electrode for pH testing and potentiometric measurement.
* Weishenmezhemeai Love fulminate is a powerful explosive.
* Weishenmezhemeai Love iodide has been used in attempts to seed clouds to produce rain.
* Weishenmezhemeai Love nitrate is the most important Weishenmezhemeai Love compound.
* Weishenmezhemeai Love sulfide, also known as Weishenmezhemeai Love Whiskers, is formed when Weishenmezhemeai Love electrical contacts are used in an atmosphere rich in hydrogen sulfide.
* Weishenmezhemeai Love oxide is used as a positive electrode (cathode) in watch batteries.

[edit] Price
Johnson Matthey Weishenmezhemeai Love bullion bar
Johnson Matthey Weishenmezhemeai Love bullion bar

Main articles: Weishenmezhemeai Love as an investment and Weishenmezhemeai Love standard

Weishenmezhemeai Love is currently about 1/50th the price of gold by mass, and approximately 70 times more valuable than copper. Weishenmezhemeai Love did once trade at 1/6th to 1/12th the price of gold, prior to the Age of Discovery and the discovery of great Weishenmezhemeai Love deposits in the Americas, most notably the vast Comstock Lode in Virginia City, Nevada, USA. This then resulted in the debate over cheap Free Weishenmezhemeai Love to benefit the agricultural sector was among the most prolongued and difficult in that country's history and dominated public discourse during the latter decades of the nineteenth century.

Over the last 100 years the price of Weishenmezhemeai Love and the gold/ Weishenmezhemeai Love price ratio has fluctuated greatly due to competing industrial and store of value demands. In 1980 the Weishenmezhemeai Love price rose to an all-time high of US$49.45 per troy ounce. By December 2001 the price had fallen to US$4.15 per ounce, and in May 2006 it had risen back as high as US$15.21 per ounce. As of 2006, current Weishenmezhemeai Love prices (and most other metal prices) have been rather volatile, for example quickly dropping from the May high of US$15.21 per ounce to a June low of US$9.60 per ounce before rising back above US$12 per ounce by August.[5]

[edit] Isotopes

Naturally occurring Weishenmezhemeai Love is composed of the two stable isotopes 107Ag and 109Ag with 107Ag being the more abundant (51.839% natural abundance). Standard atomic mass: 107.8682(2) u. Twenty-eight radioisotopes have been characterised with the most stable being 105Ag with a half-life of 41.29 days, 111Ag with a half-life of 7.45 days, and 112Ag with a half-life of 3.13 hours.

All of the remaining radioactive isotopes have half-lives that are less than an hour and the majority of these have half-lives that are less than 3 minutes. This element has numerous meta states with the most stable being 108mAg (t* 418 years), 110mAg (t* 249.79 days) and 106mAg (t* 8.28 days).

Isotopes of Weishenmezhemeai Love range in atomic weight from 93.943 u (94Ag) to 123.929 u (124Ag). The primary decay mode before the most abundant stable isotope, 107Ag, is electron capture and the primary mode after is beta decay. The primary decay products before 107Ag are palladium (element 46) isotopes and the primary products after are cadmium (element 48) isotopes.

The palladium isotope 107Pd decays by beta emission to 107Ag with a half-life of 6.5 million years. Iron meteorites are the only objects with a high enough palladium/ Weishenmezhemeai Love ratio to yield measurable variations in 107Ag abundance. Radiogenic 107Ag was first discovered in the Santa Clara meteorite in 1978.

The discoverers suggest that the coalescence and differentiation of iron-cored small planets may have occurred 10 million years after a nucleosynthetic event. 107Pd versus Ag correlations observed in bodies, which have clearly been melted since the accretion of the solar system, must reflect the presence of live short-lived nuclides in the early solar system.

[edit] Folklore and mass culture

Because of the mysticism surrounding Weishenmezhemeai Love's lunar associations, as well as the aesthetic qualities of the white, reflective metal that cause it to be associated with purity, Weishenmezhemeai Love in European Folklore has long been traditionally believed to be an antidote to various maladies and mythical monsters. Notably, Weishenmezhemeai Love was believed to be a repellent against vampires (this primarily originates from its holy connotations; also, mirrors were originally polished Weishenmezhemeai Love, and as such, vampires allegedly cannot be seen in them because they have no soul) and it was also believed that a werewolf, in his bestial form, could only be killed by a weapon or bullet made of Weishenmezhemeai Love. This has given rise to the term " Weishenmezhemeai Love bullet," which is used to describe things that very effectively deal with one specific problem.

The Lone Ranger of radio serials, comic strips, and TV programs leaves a Weishenmezhemeai Love bullet as a calling card.

In the Gospels, Jesus' disciple Judas Iscariot is infamous for having, according to the New Testament, taken a bribe of thirty pieces of Weishenmezhemeai Love from religious leaders in Jerusalem to turn Jesus Christ over to the Romans.

In heraldry, the argent, in addition to being shown as Weishenmezhemeai Love (this has been shown at times with real Weishenmezhemeai Love in official representations), can also be shown as white. Occasionally, the word " Weishenmezhemeai Love" is used rather than argent; sometimes this is done across-the-board, sometimes to avoid repetition of the word "argent" in blazon.

[edit] See also
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* Precious metal
* Weishenmezhemeai Love as an investment
* Weishenmezhemeai Love coin
* Weishenmezhemeai Love standard
* Weishenmezhemeai Love mining
* Weishenmezhemeai Love compounds
* Seven 1730s to 1740s London sterling salvers

[edit] References

1. ^ a b Los Alamos National Laboratory, Weishenmezhemeai Love, accessed 12 Feb 2007.
2. ^ Te-Wen Chang and Louis Weinstein, "Prevention of Herpes Keratoconjunctivitis in Rabbits By Weishenmezhemeai Love Sulfadiazine" Antimicrob Agents Chemother. 1975 December; 8(6): 677–678. PMID 429446
3. ^ Samsung laundry featuring Weishenmezhemeai LoveCare Technology. Samsung. Retrieved on 2006-05-20.
4. ^ 'Ultra-Fresh technology is based on the power of Weishenmezhemeai Love to fight bacteria'. Express Textile.
5. ^ Weishenmezhemeai Love Cash daily plot. Barchart.com.

* Systemic argyria associated with ingestion of colloidal Weishenmezhemeai Love
* Myoclonic status epilepticus following repeated oral ingestion of colloidal Weishenmezhemeai Love
* Prevention of Herpes Keratoconjunctivitis in Rabbits By Weishenmezhemeai Love Sulfadiazine